This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-001381, filed Jan. 8, 2002, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention generally relates to a camera apparatus such as digital cameras, which can photograph with a flash device, and especially to a flash device control technique at a close-up shot.
2. Description of the Related Art
Conventionally, in the digital camera, there is a camera apparatus, with which a flash device to illuminate flash light to a subject at a photograph is included as standard equipment.
By the way, there is a camera to which the photograph mode of the close-up shot etc. (hereafter, it is expressed as xe2x80x9cclose-up shotxe2x80x9d mode) is prepared in the digital camera. The close-up shot mode is a mode for executing the photograph (close-up) whose photograph distance to subject is the short distance within 60 cm for instance. The photograph modes are switched by switching a processing mode changing switch in the camera apparatus which has such a close-up shot mode (referring to Japanese Patent Application KOKAI Publication No. 11-298793).
At such the particular close-up shot, there is a case to want to execute the flash photography in which the flash device illuminates light from the flash device to the subject. The flash device control (flash amount control) to adjust the emission amount of the flash device is necessary in the flash photography, but there is a controllable minimum emission amount (minimum Guide Number) from the restriction on the light amount control accuracy. Therefore, the shortest distance at the flash photography is decided by the diaphragm stop and the ISO sensitivity (usually, ISO100 is set to be a standard), which is the photograph exposure condition.
The method of setting the close-up shot mode might be adopted by operating a macro button when the close-up shot is performed as mentioned above. In this case, to flash in a light emission region where the flash device stably flashes, the diaphragm stop is controlled at narrow side and the flash device is flashed.
In this method, the user must judge whether setting the close-up shot mode is necessary or not according to the photographic distance. It is general that the range of the distance of the close-up shot corresponding to the close-up shot mode is different according to the design specification of the camera apparatus. Therefore, it is not so easy to judge the setting of the close-up shot mode.
In the close-up shot region, an accurate control of the emission amount is required. The influence of the errors included with the accuracy of the distance measurement data and the mechanical inconsistency when the diaphragm is set cannot be ignored.
In addition, it is necessary to narrow the diaphragm to obtain the proper exposure in the close-up shot region, since the emission amount is too large in a state of opening the diaphragm.
A technology, which performs two or more preliminary light emission, to set the emission amount in the main light emission to an optimal emission amount at the flash light emission, is disclosed (referring to Japanese Patent Application KOKAI Publication No. 2000-162679). Since this technology controls gradually changing the emission amount at the preliminary light emission, the main light emission frequency is different according to the photographic situation. Therefore, the frequency of the preliminary light emission does not necessarily become the appropriate (minimum) frequency. Therefore, the time lag for the shutter operation is different according to the photographic situation.
An object of the present invention is to provide a technology concerning a camera apparatus, which achieves the flash device control, which adjusts automatically without requiring setting the close-up shot mode at the close-up shot.
The present invention relates to a camera apparatus, which automatically executes a flash device control (flash amount control) adaptable to the close-up shot, and the control technology thereof.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.